Trained for combat with B-17's. Moved to England, Aug-Sep 1942, and assigned to Eighth AF.

During combat, Oct 1942-Apr 1945, operated primarily against strategic targets, striking locomotive works at Lille, railroad yards at Rouen, submarine pens at Bordeaux, shipbuilding yards at Vegesack, ball-bearing works at Schweinfurt, oil plants at Merseburg, marshalling yards at Stuttgart, a foundry at Hannover, a chemical plant at Ludwigshafen, aircraft factories at Leipzig, and other objectives on the Continent.

Took part in the first penetration into Germany by heavy bombers of Eighth AF on 27 Jan 1943 by attacking U-boat yards at Wilhelmshaven.

Sgt Maynard H Smith received the Medal of Honor for his performance on 1 May 1943: when the aircraft on which he was a gunner was hit by the enemy and fires were ignited in the radio compartment and waist sections, the sergeant threw exploding ammunition overboard, manned a gun until the German fighters were driven off, administered first aid to the wounded tail gunner, and extinguished the fire.

Without fighter escort and in the face of powerful opposition, the 306th completed an assault against aircraft factories in central Germany on 11 Jan 1944, being awarded a DUC for the mission. Received another DUC for action during Big Week, the intensive campaign against the German aircraft industry, 25 Feb 1944: although hazardous weather forced supporting elements to abandon the mission, the group effectively bombarded an aircraft assembly plant at Bernberg on 22 Feb. Often supported ground forces and attacked interdictory targets in addition to its strategic operations. Helped to prepare for the invasion of Normandy by striking airfields and marshalling yards in France, Belgium, and Germany; backed the assault on 6 Jun 1944 by raiding railroad bridges and coastal guns. Assisted ground forces during the St Lo breakthrough in Jul. Covered the airborne invasion of Holland in Sep. Helped stop the advance of German armies in the Battle of the Bulge, Dec 1944-Jan 1945, by attacking airfields and marshalling yards. Bombed enemy positions in support of the airborne assault across the Rhine in Mar 1945.

Remained in the theater after V-E Day as part of United States Air Forces in Europe, and engaged in special photographic mapping duty in western Europe and North Africa. Inactivated in Germany on 25 Dec 1946.